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Purpose: Volleyball demands high physical performance including agility, speed, endurance and muscular strength. As volleyball players explore methods to achieve efficiency in these areas, nutritional supplementation has been considered a valuable adjunct to accomplish this goal. This systematic review aimed to comprehensively explore the effects of different dietary supplementation strategies on the training adaptations, antioxidant status and performance of volleyball players. Methods: A search was conducted in PubMed, Web of Science, Cochrane, Google Scholar, and EbscoHost on 28th July 2023 and updated on 12th May 2024. Studies were included if the participants were volleyball players, taking a dietary supplement and evaluated sports-related outcomes. The risk of bias was assessed using Cochrane's revised risk of bias tool, RoB2. Results: The review included 19 trials investigating supplements such as branched-chain amino acids (BCAA), creatine, N-acetylcysteine (NAC), hydroxy-methyl-butyrate (HMB), grape seed extract (GSE), nitrate, caffeine, iron and magnesium. Outcomes including vertical jump (VJ) height, endurance, oxidative stress, cell damage, muscle strength, and anaerobic and aerobic capacity were considered. Caffeine supplementation improved VJ height and agility while creatine, BCAA, HMB and mineral supplementation may improve anaerobic performance and muscle strength without a clear positive effect on VJ height, subject to a limited number of studies on each supplement. Creatine and BCAA effects were inconsistent concerning muscle damage. Conclusions: Among the investigated supplements, caffeine showed the most promising data to enhance physical performance and agility. NAC and GSE could improve antioxidant status. More research is needed to assess other supplements’ effectiveness in volleyball players. Protocol Registration: https://doi.org/10.17605/OSF.IO/8RD9V. Graphical Abstract:

Date plum (Diospyros lotus L.) fruits are a good source of bioactive compounds and antioxidants. Drying can increase the shelf life of the fruit and its applications in the food development industry. Optimizing the drying conditions can help to produce prime-quality dried date plum fruits and conserve nutrients including phytochemicals. This study used a two-factor graphics-optimal design to optimize convective drying considering the air velocity and drying temperature of date plum fruits. The independent factors considered included drying temperature (43.78–86.21 °C) and air velocities (0.54–1.96 m/s), and the responses included total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging activity of date plum fruit. The optimized drying conditions (68 °C and 1.75 m/s) resulted in desirable TPC, TFC, FRAP, and DPPH values. The findings indicated that long drying time at low temperatures significantly decreased the phenolics and antioxidants. Date plum tea with different decoction times (5, 10, and 15 min) was prepared from fruits dried at optimum conditions. A decoction time of 5 min resulted in the highest catechin, vanillic, epicatechin, syringic acid, and quercetin-3-glucoside content, which were 2.45 ± 0.04, 11.06 ± 0.11, 22.03 ± 0.11, 12.95 ± 0.08, and 9.37 ± 0.10 mg/L; respectively. In vitro gastrointestinal digestion revealed that the tea product can be a source of highly bioaccessible (> 80%) gallic acid, catechin, vanillic acid, and quercetin-3-glucoside. Applying optimized drying conditions to dehydrate date plum fruit can be useful in preparing a highly bioaccessible polyphenol-rich tea.

Bitter melon (Momordica charantia) is a rich source of phytochemicals including phenolic compounds with diverse health-promoting benefits and potential food industry application due to their antioxidant potential. Bitter melon leaves have been limitedly investigated in comparison to bitter melon fruits. The current work explores the use of green extraction methodology to optimize enhanced extraction of phenolic compounds from bitter melon leaves using ultrasonically assisted extraction and choline chloride-acetic acid (CHAC)–based natural deep eutectic solvent. Extraction using CHAC significantly improved the extraction of total phenolic compounds, total flavonoids, and individual phenolic compounds (including gallic acid, chlorogenic acid, vanillic acid, epicatechin, and quercetin-3-glucoside) in comparison to water, ethanol, and methanol. The effect of molar ratio, water content, temperature, and time on the extraction efficiency of bitter melon leaf phenolic compounds by CHAC was explored and optimized with surface response methodology (central composite design). The optimum condition for the extraction of individual phenolic compounds is a molar ratio of 1:4.35 CHAC with 20.68% water content at 75 °C for 21.23 min. Evaluation of the bioaccessibility of individual phenolic compounds concluded that the most bioaccessible compound was vanillic acid (105.00 ± 2.52%) followed by salicylic acid, chlorogenic acid, syringic acid, gallic acid, epicatechin, and quercetin-3-glucoside.

Cornelian cherry (Cornus masL.) is a rich source of (poly)phenols such as phenolic acids, flavonoids, and anthocyanins that are known for their bioactivity. This study aimed to enhance the industrial applications of this cherry’s pulp as a potential functional food ingredient. Foam-mat drying was used to produce cherry powder from cherry pulp. The convective drying process was performed at different temperatures (50, 60, 70, and 80°C) to study the effect of drying temperature on the physical properties, flow properties, microstructure, (poly)phenol content, antioxidant properties, and bioaccessibility of foam-dried cherry pulp, in comparison to freeze-dried sample. Different drying temperatures did not affect color properties. The highest gloss was determined at high temperatures (70–80°C). According to the Carr index, the fluidity increased between 18 and 22% as the temperature increased. The total phenolic content was higher at elevated temperatures (70–80°C), yet the anthocyanin content was the highest at 60°C. The flavonoid content was not affected by different drying temperatures, as well as compared to lyophilized samples. The antioxidant activity was higher in samples dried at elevated temperatures, with no significant difference in comparison to lyophilized samples. The bioaccessibility experiment showed that the lyophilized samples had significantly greater bioaccessibility in comparison to the convective dried samples, yet further investigation is required to understand the differences in bioaccessibility and bioavailability of individual polyphenols. Overall, foam-mat drying using a convective drying system could be an economic choice to preserve acceptable amounts of phenolics and antioxidants.

For more sustainable and environmentally friendly scientific research, it is essential to apply green chemistry principles in all areas of science. A possible area in which green chemistry principles can significantly influence the productivity and the quality of the outcome is extraction of natural products. The conventional toxic solvents can be replaced by environmentally friendly solvents known as deep eutectic solvents, which fortunately, due to their unique properties, can significantly improve extraction efficiency. In this literature review, the extraction of a specific class of natural products, phenolic compounds, using different types of green deep eutectic solvents has been reviewed. Within this review, the composition of those solvents used to extract different types of phenolic compounds has been discussed. In addition, the factors affecting their extraction, extracting solvent component structure, molar ratio of extracting solvent components, extraction temperature, solid to extraction solvent ratio, and water content, have been evaluated.

•Black mulberry contained higher Mg and Ca content than other mulberries.•Similar Mn, Zn, and Cu content was present in the mulberries.•Black mulberry contained the greatest amount of C18:0 and C18:2n6.•Red mulberry had the highest C16:1n7 and C20:00 content.•White mulberry had a higher amount of C19:1n6 and C19:1n7.